This (now shorter) series expands the existing GICv4 support to deal
with the new GICv4.1 architecture, which comes with a set of major
improvements compared to v4.0:
- One architectural doorbell per vcpu, instead of one doorbell per VLPI
- Doorbell entirely managed by the HW, with an "at most once" delivery
guarantee per non-residency phase and only when requested by the
hypervisor
- A shared memory scheme between ITSs and redistributors, allowing for an
optimised residency sequence (the use of VMOVP becomes less frequent)
- Support for direct virtual SGI delivery (the injection path still involves
the hypervisor), at the cost of losing the active state on SGIs. It
shouldn't be a big deal, but some guest operating systems might notice
(Linux definitely won't care).
On the other hand, public documentation is not available yet, so that's a
bit annoying...
The series is roughly organised in 3 parts:
(1) v4.1 doorbell management
(2) Virtual SGI support
(3) Plumbing of virtual SGIs in KVM
Notes:
- The whole thing is tested on a FVP model, which can be obtained
free of charge on ARM's developer website. It requires you to
create an account, unfortunately... You'll need a fix for the
devicetree that is in the kernel tree (should be merged before
the 5.6 release).
- This series has uncovered a behaviour that looks like a HW bug on
the Cavium ThunderX (aka TX1) platform. I'd very much welcome some
clarification from the Marvell/Cavium folks on Cc, as well as an
official erratum number if this happens to be an actual bug.
[v3 update]
People have ignored for two months now, and it is fairly obvious
that support for this machine is slowly bit-rotting. Maybe I'll
drop the patch and instead start the process of removing all TX1
support from the kernel (we'd certainly be better off without it).
[v4 update]
TX1 is now broken in mainline, and nobody cares. Make of this what
you want.
* From v3 [3]:
- Rebased on v5.6-rc1
- Considerably smaller thanks to the initial patches being merged
- Small bug fix after the v5.6 merge window
* From v2 [2]:
- Another bunch of fixes thanks to Zenghui Yu's very careful review
- HW-accelerated SGIs are now optional thanks to new architected
discovery/selection bits exposed by KVM and used by the guest kernel
- Rebased on v5.5-rc2
* From v1 [1]:
- A bunch of minor reworks after Zenghui Yu's review
- A workaround for what looks like a new and unexpected TX1 bug
- A subtle reorder of the series so that some patches can go in early
[1] https://lore.kernel.org/lkml/[email protected]/
[2] https://lore.kernel.org/lkml/[email protected]/
[3] https://lore.kernel.org/r/[email protected]/
Marc Zyngier (20):
irqchip/gic-v4.1: Skip absent CPUs while iterating over redistributors
irqchip/gic-v3: Use SGIs without active state if offered
irqchip/gic-v4.1: Advertise support v4.1 to KVM
irqchip/gic-v4.1: Map the ITS SGIR register page
irqchip/gic-v4.1: Plumb skeletal VSGI irqchip
irqchip/gic-v4.1: Add initial SGI configuration
irqchip/gic-v4.1: Plumb mask/unmask SGI callbacks
irqchip/gic-v4.1: Plumb get/set_irqchip_state SGI callbacks
irqchip/gic-v4.1: Plumb set_vcpu_affinity SGI callbacks
irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction
layer
irqchip/gic-v4.1: Add VSGI allocation/teardown
irqchip/gic-v4.1: Add VSGI property setup
irqchip/gic-v4.1: Eagerly vmap vPEs
KVM: arm64: GICv4.1: Let doorbells be auto-enabled
KVM: arm64: GICv4.1: Add direct injection capability to SGI registers
KVM: arm64: GICv4.1: Allow SGIs to switch between HW and SW interrupts
KVM: arm64: GICv4.1: Plumb SGI implementation selection in the
distributor
KVM: arm64: GICv4.1: Reload VLPI configuration on distributor
enable/disable
KVM: arm64: GICv4.1: Allow non-trapping WFI when using HW SGIs
KVM: arm64: GICv4.1: Expose HW-based SGIs in debugfs
arch/arm/include/asm/kvm_host.h | 1 +
arch/arm64/include/asm/kvm_emulate.h | 3 +-
arch/arm64/include/asm/kvm_host.h | 1 +
drivers/irqchip/irq-gic-v3-its.c | 301 ++++++++++++++++++++++++-
drivers/irqchip/irq-gic-v3.c | 12 +-
drivers/irqchip/irq-gic-v4.c | 134 ++++++++++-
include/kvm/arm_vgic.h | 4 +
include/linux/irqchip/arm-gic-common.h | 2 +
include/linux/irqchip/arm-gic-v3.h | 19 +-
include/linux/irqchip/arm-gic-v4.h | 20 +-
virt/kvm/arm/arm.c | 8 +
virt/kvm/arm/vgic/vgic-debug.c | 14 +-
virt/kvm/arm/vgic/vgic-mmio-v3.c | 68 +++++-
virt/kvm/arm/vgic/vgic-mmio.c | 88 +++++++-
virt/kvm/arm/vgic/vgic-v3.c | 6 +-
virt/kvm/arm/vgic/vgic-v4.c | 139 ++++++++++--
virt/kvm/arm/vgic/vgic.h | 1 +
17 files changed, 763 insertions(+), 58 deletions(-)
--
2.20.1
One of the new features of GICv4.1 is to allow virtual SGIs to be
directly signaled to a VPE. For that, the ITS has grown a new
64kB page containing only a single register that is used to
signal a SGI to a given VPE.
Add a second mapping covering this new 64kB range, and take this
opportunity to limit the original mapping to 64kB, which is enough
to cover the span of the ITS registers.
Signed-off-by: Marc Zyngier <[email protected]>
---
drivers/irqchip/irq-gic-v3-its.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 9a7854416b89..d6201443b406 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -96,6 +96,7 @@ struct its_node {
struct mutex dev_alloc_lock;
struct list_head entry;
void __iomem *base;
+ void __iomem *sgir_base;
phys_addr_t phys_base;
struct its_cmd_block *cmd_base;
struct its_cmd_block *cmd_write;
@@ -4408,7 +4409,7 @@ static int __init its_probe_one(struct resource *res,
struct page *page;
int err;
- its_base = ioremap(res->start, resource_size(res));
+ its_base = ioremap(res->start, SZ_64K);
if (!its_base) {
pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start);
return -ENOMEM;
@@ -4459,6 +4460,13 @@ static int __init its_probe_one(struct resource *res,
if (is_v4_1(its)) {
u32 svpet = FIELD_GET(GITS_TYPER_SVPET, typer);
+
+ its->sgir_base = ioremap(res->start + SZ_128K, SZ_64K);
+ if (!its->sgir_base) {
+ err = -ENOMEM;
+ goto out_free_its;
+ }
+
its->mpidr = readl_relaxed(its_base + GITS_MPIDR);
pr_info("ITS@%pa: Using GICv4.1 mode %08x %08x\n",
@@ -4472,7 +4480,7 @@ static int __init its_probe_one(struct resource *res,
get_order(ITS_CMD_QUEUE_SZ));
if (!page) {
err = -ENOMEM;
- goto out_free_its;
+ goto out_unmap_sgir;
}
its->cmd_base = (void *)page_address(page);
its->cmd_write = its->cmd_base;
@@ -4539,6 +4547,9 @@ static int __init its_probe_one(struct resource *res,
its_free_tables(its);
out_free_cmd:
free_pages((unsigned long)its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
+out_unmap_sgir:
+ if (its->sgir_base)
+ iounmap(its->sgir_base);
out_free_its:
kfree(its);
out_unmap:
--
2.20.1
In order to hide some of the differences between v4.0 and v4.1, move
the doorbell management out of the KVM code, and into the GICv4-specific
layer. This allows the calling code to ask for the doorbell when blocking,
and otherwise to leave the doorbell permanently disabled.
This matches the v4.1 code perfectly, and only results in a minor
refactoring of the v4.0 code.
Signed-off-by: Marc Zyngier <[email protected]>
---
drivers/irqchip/irq-gic-v4.c | 45 +++++++++++++++++++++++++++---
include/kvm/arm_vgic.h | 1 +
include/linux/irqchip/arm-gic-v4.h | 3 +-
virt/kvm/arm/vgic/vgic-v3.c | 4 ++-
virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++------------
5 files changed, 61 insertions(+), 26 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index c01910d53f9e..117ba6db023d 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -87,6 +87,11 @@ static struct irq_domain *gic_domain;
static const struct irq_domain_ops *vpe_domain_ops;
static const struct irq_domain_ops *sgi_domain_ops;
+static bool has_v4_1(void)
+{
+ return !!sgi_domain_ops;
+}
+
int its_alloc_vcpu_irqs(struct its_vm *vm)
{
int vpe_base_irq, i;
@@ -139,18 +144,50 @@ static int its_send_vpe_cmd(struct its_vpe *vpe, struct its_cmd_info *info)
return irq_set_vcpu_affinity(vpe->irq, info);
}
-int its_schedule_vpe(struct its_vpe *vpe, bool on)
+int its_make_vpe_non_resident(struct its_vpe *vpe, bool db)
{
- struct its_cmd_info info;
+ struct irq_desc *desc = irq_to_desc(vpe->irq);
+ struct its_cmd_info info = { };
int ret;
WARN_ON(preemptible());
- info.cmd_type = on ? SCHEDULE_VPE : DESCHEDULE_VPE;
+ info.cmd_type = DESCHEDULE_VPE;
+ if (has_v4_1()) {
+ /* GICv4.1 can directly deal with doorbells */
+ info.req_db = db;
+ } else {
+ /* Undo the nested disable_irq() calls... */
+ while (db && irqd_irq_disabled(&desc->irq_data))
+ enable_irq(vpe->irq);
+ }
+
+ ret = its_send_vpe_cmd(vpe, &info);
+ if (!ret)
+ vpe->resident = false;
+
+ return ret;
+}
+
+int its_make_vpe_resident(struct its_vpe *vpe, bool g0en, bool g1en)
+{
+ struct its_cmd_info info = { };
+ int ret;
+
+ WARN_ON(preemptible());
+
+ info.cmd_type = SCHEDULE_VPE;
+ if (has_v4_1()) {
+ info.g0en = g0en;
+ info.g1en = g1en;
+ } else {
+ /* Disabled the doorbell, as we're about to enter the guest */
+ disable_irq_nosync(vpe->irq);
+ }
ret = its_send_vpe_cmd(vpe, &info);
if (!ret)
- vpe->resident = on;
+ vpe->resident = true;
return ret;
}
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 9d53f545a3d5..63457908c9c4 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -70,6 +70,7 @@ struct vgic_global {
/* Hardware has GICv4? */
bool has_gicv4;
+ bool has_gicv4_1;
/* GIC system register CPU interface */
struct static_key_false gicv3_cpuif;
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index a1a9d40266f5..cca4198fa1d5 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -120,7 +120,8 @@ struct its_cmd_info {
int its_alloc_vcpu_irqs(struct its_vm *vm);
void its_free_vcpu_irqs(struct its_vm *vm);
-int its_schedule_vpe(struct its_vpe *vpe, bool on);
+int its_make_vpe_resident(struct its_vpe *vpe, bool g0en, bool g1en);
+int its_make_vpe_non_resident(struct its_vpe *vpe, bool db);
int its_invall_vpe(struct its_vpe *vpe);
int its_map_vlpi(int irq, struct its_vlpi_map *map);
int its_get_vlpi(int irq, struct its_vlpi_map *map);
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index f45635a6f0ec..1bc09b523486 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -595,7 +595,9 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
/* GICv4 support? */
if (info->has_v4) {
kvm_vgic_global_state.has_gicv4 = gicv4_enable;
- kvm_info("GICv4 support %sabled\n",
+ kvm_vgic_global_state.has_gicv4_1 = info->has_v4_1 && gicv4_enable;
+ kvm_info("GICv4%s support %sabled\n",
+ kvm_vgic_global_state.has_gicv4_1 ? ".1" : "",
gicv4_enable ? "en" : "dis");
}
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 46f875589c47..1eb0f8c76219 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -67,10 +67,10 @@
* it. And if we've migrated our vcpu from one CPU to another, we must
* tell the ITS (so that the messages reach the right redistributor).
* This is done in two steps: first issue a irq_set_affinity() on the
- * irq corresponding to the vcpu, then call its_schedule_vpe(). You
- * must be in a non-preemptible context. On exit, another call to
- * its_schedule_vpe() tells the redistributor that we're done with the
- * vcpu.
+ * irq corresponding to the vcpu, then call its_make_vpe_resident().
+ * You must be in a non-preemptible context. On exit, a call to
+ * its_make_vpe_non_resident() tells the redistributor that we're done
+ * with the vcpu.
*
* Finally, the doorbell handling: Each vcpu is allocated an interrupt
* which will fire each time a VLPI is made pending whilst the vcpu is
@@ -86,7 +86,8 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
struct kvm_vcpu *vcpu = info;
/* We got the message, no need to fire again */
- if (!irqd_irq_disabled(&irq_to_desc(irq)->irq_data))
+ if (!kvm_vgic_global_state.has_gicv4_1 &&
+ !irqd_irq_disabled(&irq_to_desc(irq)->irq_data))
disable_irq_nosync(irq);
vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
@@ -199,19 +200,11 @@ void vgic_v4_teardown(struct kvm *kvm)
int vgic_v4_put(struct kvm_vcpu *vcpu, bool need_db)
{
struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
- struct irq_desc *desc = irq_to_desc(vpe->irq);
if (!vgic_supports_direct_msis(vcpu->kvm) || !vpe->resident)
return 0;
- /*
- * If blocking, a doorbell is required. Undo the nested
- * disable_irq() calls...
- */
- while (need_db && irqd_irq_disabled(&desc->irq_data))
- enable_irq(vpe->irq);
-
- return its_schedule_vpe(vpe, false);
+ return its_make_vpe_non_resident(vpe, need_db);
}
int vgic_v4_load(struct kvm_vcpu *vcpu)
@@ -232,18 +225,19 @@ int vgic_v4_load(struct kvm_vcpu *vcpu)
if (err)
return err;
- /* Disabled the doorbell, as we're about to enter the guest */
- disable_irq_nosync(vpe->irq);
-
- err = its_schedule_vpe(vpe, true);
+ err = its_make_vpe_resident(vpe, false, vcpu->kvm->arch.vgic.enabled);
if (err)
return err;
/*
* Now that the VPE is resident, let's get rid of a potential
- * doorbell interrupt that would still be pending.
+ * doorbell interrupt that would still be pending. This is a
+ * GICv4.0 only "feature"...
*/
- return irq_set_irqchip_state(vpe->irq, IRQCHIP_STATE_PENDING, false);
+ if (!kvm_vgic_global_state.has_gicv4_1)
+ err = irq_set_irqchip_state(vpe->irq, IRQCHIP_STATE_PENDING, false);
+
+ return err;
}
static struct vgic_its *vgic_get_its(struct kvm *kvm,
--
2.20.1
The GICv4.1 architecture gives the hypervisor the option to let
the guest choose whether it wants the good old SGIs with an
active state, or the new, HW-based ones that do not have one.
For this, plumb the configuration of SGIs into the GICv3 MMIO
handling, present the GICD_TYPER2.nASSGIcap to the guest,
and handle the GICD_CTLR.nASSGIreq setting.
Signed-off-by: Marc Zyngier <[email protected]>
---
virt/kvm/arm/vgic/vgic-mmio-v3.c | 48 ++++++++++++++++++++++++++++++--
1 file changed, 46 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index de89da76a379..442f3b8c2559 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -3,6 +3,7 @@
* VGICv3 MMIO handling functions
*/
+#include <linux/bitfield.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
@@ -70,6 +71,8 @@ static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
if (vgic->enabled)
value |= GICD_CTLR_ENABLE_SS_G1;
value |= GICD_CTLR_ARE_NS | GICD_CTLR_DS;
+ if (kvm_vgic_global_state.has_gicv4_1 && vgic->nassgireq)
+ value |= GICD_CTLR_nASSGIreq;
break;
case GICD_TYPER:
value = vgic->nr_spis + VGIC_NR_PRIVATE_IRQS;
@@ -81,6 +84,10 @@ static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
value |= (INTERRUPT_ID_BITS_SPIS - 1) << 19;
}
break;
+ case GICD_TYPER2:
+ if (kvm_vgic_global_state.has_gicv4_1)
+ value = GICD_TYPER2_nASSGIcap;
+ break;
case GICD_IIDR:
value = (PRODUCT_ID_KVM << GICD_IIDR_PRODUCT_ID_SHIFT) |
(vgic->implementation_rev << GICD_IIDR_REVISION_SHIFT) |
@@ -98,17 +105,43 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
unsigned long val)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
- bool was_enabled = dist->enabled;
switch (addr & 0x0c) {
- case GICD_CTLR:
+ case GICD_CTLR: {
+ bool was_enabled, is_hwsgi;
+
+ mutex_lock(&vcpu->kvm->lock);
+
+ was_enabled = dist->enabled;
+ is_hwsgi = dist->nassgireq;
+
dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;
+ /* Not a GICv4.1? No HW SGIs */
+ if (!kvm_vgic_global_state.has_gicv4_1)
+ val &= ~GICD_CTLR_nASSGIreq;
+
+ /* Dist stays enabled? nASSGIreq is RO */
+ if (was_enabled && dist->enabled) {
+ val &= ~GICD_CTLR_nASSGIreq;
+ val |= FIELD_PREP(GICD_CTLR_nASSGIreq, is_hwsgi);
+ }
+
+ /* Switching HW SGIs? */
+ dist->nassgireq = val & GICD_CTLR_nASSGIreq;
+ if (is_hwsgi != dist->nassgireq)
+ vgic_v4_configure_vsgis(vcpu->kvm);
+
if (!was_enabled && dist->enabled)
vgic_kick_vcpus(vcpu->kvm);
+
+ mutex_unlock(&vcpu->kvm->lock);
break;
+ }
case GICD_TYPER:
+ case GICD_TYPER2:
case GICD_IIDR:
+ /* This is at best for documentation purposes... */
return;
}
}
@@ -117,10 +150,21 @@ static int vgic_mmio_uaccess_write_v3_misc(struct kvm_vcpu *vcpu,
gpa_t addr, unsigned int len,
unsigned long val)
{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
switch (addr & 0x0c) {
case GICD_IIDR:
if (val != vgic_mmio_read_v3_misc(vcpu, addr, len))
return -EINVAL;
+ return 0;
+ case GICD_CTLR:
+ /* Not a GICv4.1? No HW SGIs */
+ if (!kvm_vgic_global_state.has_gicv4_1)
+ val &= ~GICD_CTLR_nASSGIreq;
+
+ dist->enabled = val & GICD_CTLR_ENABLE_SS_G1;
+ dist->nassgireq = val & GICD_CTLR_nASSGIreq;
+ return 0;
}
vgic_mmio_write_v3_misc(vcpu, addr, len, val);
--
2.20.1
The vgic-state debugfs file could do with showing the pending state
of the HW-backed SGIs. Plug it into the low-level code.
Signed-off-by: Marc Zyngier <[email protected]>
---
virt/kvm/arm/vgic/vgic-debug.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/arm/vgic/vgic-debug.c b/virt/kvm/arm/vgic/vgic-debug.c
index cc12fe9b2df3..b13a9e3f99dd 100644
--- a/virt/kvm/arm/vgic/vgic-debug.c
+++ b/virt/kvm/arm/vgic/vgic-debug.c
@@ -178,6 +178,8 @@ static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
struct kvm_vcpu *vcpu)
{
char *type;
+ bool pending;
+
if (irq->intid < VGIC_NR_SGIS)
type = "SGI";
else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
@@ -190,6 +192,16 @@ static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
print_header(s, irq, vcpu);
+ pending = irq->pending_latch;
+ if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ int err;
+
+ err = irq_get_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ &pending);
+ WARN_ON_ONCE(err);
+ }
+
seq_printf(s, " %s %4d "
" %2d "
"%d%d%d%d%d%d%d "
@@ -201,7 +213,7 @@ static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
"\n",
type, irq->intid,
(irq->target_vcpu) ? irq->target_vcpu->vcpu_id : -1,
- irq->pending_latch,
+ pending,
irq->line_level,
irq->active,
irq->enabled,
--
2.20.1
In order to let a guest buy in the new, active-less SGIs, we
need to be able to switch between the two modes.
Handle this by stopping all guest activity, transfer the state
from one mode to the other, and resume the guest.
Signed-off-by: Marc Zyngier <[email protected]>
---
include/kvm/arm_vgic.h | 3 ++
virt/kvm/arm/vgic/vgic-v3.c | 2 +
virt/kvm/arm/vgic/vgic-v4.c | 96 +++++++++++++++++++++++++++++++++++++
virt/kvm/arm/vgic/vgic.h | 1 +
4 files changed, 102 insertions(+)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 63457908c9c4..69f4164d6477 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -231,6 +231,9 @@ struct vgic_dist {
/* distributor enabled */
bool enabled;
+ /* Wants SGIs without active state */
+ bool nassgireq;
+
struct vgic_irq *spis;
struct vgic_io_device dist_iodev;
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 1bc09b523486..2c9fc13e2c59 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm)
goto out;
}
+ if (kvm_vgic_global_state.has_gicv4_1)
+ vgic_v4_configure_vsgis(kvm);
dist->ready = true;
out:
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index c2fcde104ea2..063785fd2dc7 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -97,6 +97,102 @@ static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
return IRQ_HANDLED;
}
+static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct vgic_irq *irq)
+{
+ vpe->sgi_config[irq->intid].enabled = irq->enabled;
+ vpe->sgi_config[irq->intid].group = irq->group;
+ vpe->sgi_config[irq->intid].priority = irq->priority;
+}
+
+static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu)
+{
+ struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe;
+ int i;
+
+ /*
+ * With GICv4.1, every virtual SGI can be directly injected. So
+ * let's pretend that they are HW interrupts, tied to a host
+ * IRQ. The SGI code will do its magic.
+ */
+ for (i = 0; i < VGIC_NR_SGIS; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i);
+ struct irq_desc *desc;
+ int ret;
+
+ if (irq->hw) {
+ vgic_put_irq(vcpu->kvm, irq);
+ continue;
+ }
+
+ irq->hw = true;
+ irq->host_irq = irq_find_mapping(vpe->sgi_domain, i);
+ vgic_v4_sync_sgi_config(vpe, irq);
+ /*
+ * SGIs are initialised as disabled. Enable them if
+ * required by the rest of the VGIC init code.
+ */
+ desc = irq_to_desc(irq->host_irq);
+ ret = irq_domain_activate_irq(irq_desc_get_irq_data(desc),
+ false);
+ if (!WARN_ON(ret)) {
+ /* Transfer pending state */
+ ret = irq_set_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ irq->pending_latch);
+ WARN_ON(ret);
+ irq->pending_latch = false;
+ }
+
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+}
+
+static void vgic_v4_disable_vsgis(struct kvm_vcpu *vcpu)
+{
+ int i;
+
+ for (i = 0; i < VGIC_NR_SGIS; i++) {
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i);
+ struct irq_desc *desc;
+ int ret;
+
+ if (!irq->hw) {
+ vgic_put_irq(vcpu->kvm, irq);
+ continue;
+ }
+
+ irq->hw = false;
+ ret = irq_get_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ &irq->pending_latch);
+ WARN_ON(ret);
+
+ desc = irq_to_desc(irq->host_irq);
+ irq_domain_deactivate_irq(irq_desc_get_irq_data(desc));
+
+ vgic_put_irq(vcpu->kvm, irq);
+ }
+}
+
+/* Must be called with the kvm lock held */
+void vgic_v4_configure_vsgis(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ kvm_arm_halt_guest(kvm);
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (dist->nassgireq)
+ vgic_v4_enable_vsgis(vcpu);
+ else
+ vgic_v4_disable_vsgis(vcpu);
+ }
+
+ kvm_arm_resume_guest(kvm);
+}
+
/**
* vgic_v4_init - Initialize the GICv4 data structures
* @kvm: Pointer to the VM being initialized
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index c7fefd6b1c80..769e4802645e 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -316,5 +316,6 @@ void vgic_its_invalidate_cache(struct kvm *kvm);
bool vgic_supports_direct_msis(struct kvm *kvm);
int vgic_v4_init(struct kvm *kvm);
void vgic_v4_teardown(struct kvm *kvm);
+void vgic_v4_configure_vsgis(struct kvm *kvm);
#endif
--
2.20.1
Now that we have HW-accelerated SGIs being delivered to VPEs, it
becomes required to map the VPEs on all ITSs instead of relying
on the lazy approach that we would use when using the ITS-list
mechanism.
Signed-off-by: Marc Zyngier <[email protected]>
---
drivers/irqchip/irq-gic-v3-its.c | 39 +++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 8 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index a2e824eae43f..7656b353a95f 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1554,12 +1554,31 @@ static int its_irq_set_irqchip_state(struct irq_data *d,
return 0;
}
+/*
+ * Two favourable cases:
+ *
+ * (a) Either we have a GICv4.1, and all vPEs have to be mapped at all times
+ * for vSGI delivery
+ *
+ * (b) Or the ITSs do not use a list map, meaning that VMOVP is cheap enough
+ * and we're better off mapping all VPEs always
+ *
+ * If neither (a) nor (b) is true, then we map vPEs on demand.
+ *
+ */
+static bool gic_requires_eager_mapping(void)
+{
+ if (!its_list_map || gic_rdists->has_rvpeid)
+ return true;
+
+ return false;
+}
+
static void its_map_vm(struct its_node *its, struct its_vm *vm)
{
unsigned long flags;
- /* Not using the ITS list? Everything is always mapped. */
- if (!its_list_map)
+ if (gic_requires_eager_mapping())
return;
raw_spin_lock_irqsave(&vmovp_lock, flags);
@@ -1593,7 +1612,7 @@ static void its_unmap_vm(struct its_node *its, struct its_vm *vm)
unsigned long flags;
/* Not using the ITS list? Everything is always mapped. */
- if (!its_list_map)
+ if (gic_requires_eager_mapping())
return;
raw_spin_lock_irqsave(&vmovp_lock, flags);
@@ -4192,8 +4211,12 @@ static int its_vpe_irq_domain_activate(struct irq_domain *domain,
struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
struct its_node *its;
- /* If we use the list map, we issue VMAPP on demand... */
- if (its_list_map)
+ /*
+ * If we use the list map, we issue VMAPP on demand... Unless
+ * we're on a GICv4.1 and we eagerly map the VPE on all ITSs
+ * so that VSGIs can work.
+ */
+ if (!gic_requires_eager_mapping())
return 0;
/* Map the VPE to the first possible CPU */
@@ -4219,10 +4242,10 @@ static void its_vpe_irq_domain_deactivate(struct irq_domain *domain,
struct its_node *its;
/*
- * If we use the list map, we unmap the VPE once no VLPIs are
- * associated with the VM.
+ * If we use the list map on GICv4.0, we unmap the VPE once no
+ * VLPIs are associated with the VM.
*/
- if (its_list_map)
+ if (!gic_requires_eager_mapping())
return;
list_for_each_entry(its, &its_nodes, entry) {
--
2.20.1
Just like for VLPIs, it is beneficial to avoid trapping on WFI when the
vcpu is using the GICv4.1 SGIs.
Add such a check to vcpu_clear_wfx_traps().
Signed-off-by: Marc Zyngier <[email protected]>
---
arch/arm64/include/asm/kvm_emulate.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 688c63412cc2..755654c839e2 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -89,7 +89,8 @@ static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
static inline void vcpu_clear_wfx_traps(struct kvm_vcpu *vcpu)
{
vcpu->arch.hcr_el2 &= ~HCR_TWE;
- if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count))
+ if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
+ vcpu->kvm->arch.vgic.nassgireq)
vcpu->arch.hcr_el2 &= ~HCR_TWI;
else
vcpu->arch.hcr_el2 |= HCR_TWI;
--
2.20.1
Allocate per-VPE SGIs when initializing the GIC-specific part of the
VPE data structure.
Signed-off-by: Marc Zyngier <[email protected]>
---
drivers/irqchip/irq-gic-v4.c | 68 +++++++++++++++++++++++++++++-
include/linux/irqchip/arm-gic-v4.h | 2 +
2 files changed, 69 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index 117ba6db023d..99b33f60ac63 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -92,6 +92,47 @@ static bool has_v4_1(void)
return !!sgi_domain_ops;
}
+static int its_alloc_vcpu_sgis(struct its_vpe *vpe, int idx)
+{
+ char *name;
+ int sgi_base;
+
+ if (!has_v4_1())
+ return 0;
+
+ name = kasprintf(GFP_KERNEL, "GICv4-sgi-%d", task_pid_nr(current));
+ if (!name)
+ goto err;
+
+ vpe->fwnode = irq_domain_alloc_named_id_fwnode(name, idx);
+ if (!vpe->fwnode)
+ goto err;
+
+ kfree(name);
+ name = NULL;
+
+ vpe->sgi_domain = irq_domain_create_linear(vpe->fwnode, 16,
+ sgi_domain_ops, vpe);
+ if (!vpe->sgi_domain)
+ goto err;
+
+ sgi_base = __irq_domain_alloc_irqs(vpe->sgi_domain, -1, 16,
+ NUMA_NO_NODE, vpe,
+ false, NULL);
+ if (sgi_base <= 0)
+ goto err;
+
+ return 0;
+
+err:
+ if (vpe->sgi_domain)
+ irq_domain_remove(vpe->sgi_domain);
+ if (vpe->fwnode)
+ irq_domain_free_fwnode(vpe->fwnode);
+ kfree(name);
+ return -ENOMEM;
+}
+
int its_alloc_vcpu_irqs(struct its_vm *vm)
{
int vpe_base_irq, i;
@@ -118,8 +159,13 @@ int its_alloc_vcpu_irqs(struct its_vm *vm)
if (vpe_base_irq <= 0)
goto err;
- for (i = 0; i < vm->nr_vpes; i++)
+ for (i = 0; i < vm->nr_vpes; i++) {
+ int ret;
vm->vpes[i]->irq = vpe_base_irq + i;
+ ret = its_alloc_vcpu_sgis(vm->vpes[i], i);
+ if (ret)
+ goto err;
+ }
return 0;
@@ -132,8 +178,28 @@ int its_alloc_vcpu_irqs(struct its_vm *vm)
return -ENOMEM;
}
+static void its_free_sgi_irqs(struct its_vm *vm)
+{
+ int i;
+
+ if (!has_v4_1())
+ return;
+
+ for (i = 0; i < vm->nr_vpes; i++) {
+ unsigned int irq = irq_find_mapping(vm->vpes[i]->sgi_domain, 0);
+
+ if (WARN_ON(!irq))
+ continue;
+
+ irq_domain_free_irqs(irq, 16);
+ irq_domain_remove(vm->vpes[i]->sgi_domain);
+ irq_domain_free_fwnode(vm->vpes[i]->fwnode);
+ }
+}
+
void its_free_vcpu_irqs(struct its_vm *vm)
{
+ its_free_sgi_irqs(vm);
irq_domain_free_irqs(vm->vpes[0]->irq, vm->nr_vpes);
irq_domain_remove(vm->domain);
irq_domain_free_fwnode(vm->fwnode);
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index cca4198fa1d5..9fbd0418f569 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -49,6 +49,8 @@ struct its_vpe {
};
/* GICv4.1 implementations */
struct {
+ struct fwnode_handle *fwnode;
+ struct irq_domain *sgi_domain;
struct {
u8 priority;
bool enabled;
--
2.20.1
Each time a Group-enable bit gets flipped, the state of these bits
needs to be forwarded to the hardware. This is a pretty heavy
handed operation, requiring all vcpus to reload their GICv4
configuration. It is thus implemented as a new request type.
Of course, we only support Group-1 for now...
Signed-off-by: Marc Zyngier <[email protected]>
---
arch/arm/include/asm/kvm_host.h | 1 +
arch/arm64/include/asm/kvm_host.h | 1 +
virt/kvm/arm/arm.c | 8 ++++++++
virt/kvm/arm/vgic/vgic-mmio-v3.c | 5 ++++-
4 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index c3314b286a61..7104babef15a 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -39,6 +39,7 @@
#define KVM_REQ_IRQ_PENDING KVM_ARCH_REQ(1)
#define KVM_REQ_VCPU_RESET KVM_ARCH_REQ(2)
#define KVM_REQ_RECORD_STEAL KVM_ARCH_REQ(3)
+#define KVM_REQ_RELOAD_GICv4 KVM_ARCH_REQ(4)
DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index d87aa609d2b6..90b86f349ceb 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -44,6 +44,7 @@
#define KVM_REQ_IRQ_PENDING KVM_ARCH_REQ(1)
#define KVM_REQ_VCPU_RESET KVM_ARCH_REQ(2)
#define KVM_REQ_RECORD_STEAL KVM_ARCH_REQ(3)
+#define KVM_REQ_RELOAD_GICv4 KVM_ARCH_REQ(4)
DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index d65a0faa46d8..d21e17b7af45 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -625,6 +625,14 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu)
if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu))
kvm_update_stolen_time(vcpu);
+
+ if (kvm_check_request(KVM_REQ_RELOAD_GICv4, vcpu)) {
+ /* The distributor enable bits were changed */
+ preempt_disable();
+ vgic_v4_put(vcpu, false);
+ vgic_v4_load(vcpu);
+ preempt_enable();
+ }
}
}
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 442f3b8c2559..48fd9fc229a2 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -132,7 +132,10 @@ static void vgic_mmio_write_v3_misc(struct kvm_vcpu *vcpu,
if (is_hwsgi != dist->nassgireq)
vgic_v4_configure_vsgis(vcpu->kvm);
- if (!was_enabled && dist->enabled)
+ if (kvm_vgic_global_state.has_gicv4_1 &&
+ was_enabled != dist->enabled)
+ kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_RELOAD_GICv4);
+ else if (!was_enabled && dist->enabled)
vgic_kick_vcpus(vcpu->kvm);
mutex_unlock(&vcpu->kvm->lock);
--
2.20.1
As GICv4.1 understands the life cycle of doorbells (instead of
just randomly firing them at the most inconvenient time), just
enable them at irq_request time, and be done with it.
Signed-off-by: Marc Zyngier <[email protected]>
---
virt/kvm/arm/vgic/vgic-v4.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index 1eb0f8c76219..c2fcde104ea2 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -141,6 +141,7 @@ int vgic_v4_init(struct kvm *kvm)
kvm_for_each_vcpu(i, vcpu, kvm) {
int irq = dist->its_vm.vpes[i]->irq;
+ unsigned long irq_flags = DB_IRQ_FLAGS;
/*
* Don't automatically enable the doorbell, as we're
@@ -148,8 +149,14 @@ int vgic_v4_init(struct kvm *kvm)
* blocked. Also disable the lazy disabling, as the
* doorbell could kick us out of the guest too
* early...
+ *
+ * On GICv4.1, the doorbell is managed in HW and must
+ * be left enabled.
*/
- irq_set_status_flags(irq, DB_IRQ_FLAGS);
+ if (kvm_vgic_global_state.has_gicv4_1)
+ irq_flags &= ~IRQ_NOAUTOEN;
+ irq_set_status_flags(irq, irq_flags);
+
ret = request_irq(irq, vgic_v4_doorbell_handler,
0, "vcpu", vcpu);
if (ret) {
--
2.20.1
Add the SGI configuration entry point for KVM to use.
Signed-off-by: Marc Zyngier <[email protected]>
---
drivers/irqchip/irq-gic-v4.c | 13 +++++++++++++
include/linux/irqchip/arm-gic-v4.h | 1 +
2 files changed, 14 insertions(+)
diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index 99b33f60ac63..f3f06c5c7e54 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -320,6 +320,19 @@ int its_prop_update_vlpi(int irq, u8 config, bool inv)
return irq_set_vcpu_affinity(irq, &info);
}
+int its_prop_update_vsgi(int irq, u8 priority, bool group)
+{
+ struct its_cmd_info info = {
+ .cmd_type = PROP_UPDATE_SGI,
+ {
+ .priority = priority,
+ .group = group,
+ },
+ };
+
+ return irq_set_vcpu_affinity(irq, &info);
+}
+
int its_init_v4(struct irq_domain *domain,
const struct irq_domain_ops *vpe_ops,
const struct irq_domain_ops *sgi_ops)
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index 9fbd0418f569..46c167a6349f 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -129,6 +129,7 @@ int its_map_vlpi(int irq, struct its_vlpi_map *map);
int its_get_vlpi(int irq, struct its_vlpi_map *map);
int its_unmap_vlpi(int irq);
int its_prop_update_vlpi(int irq, u8 config, bool inv);
+int its_prop_update_vsgi(int irq, u8 priority, bool group);
struct irq_domain_ops;
int its_init_v4(struct irq_domain *domain,
--
2.20.1
Most of the GICv3 emulation code that deals with SGIs now has to be
aware of the v4.1 capabilities in order to benefit from it.
Add such support, keyed on the interrupt having the hw flag set and
being a SGI.
Signed-off-by: Marc Zyngier <[email protected]>
---
virt/kvm/arm/vgic/vgic-mmio-v3.c | 15 +++++-
virt/kvm/arm/vgic/vgic-mmio.c | 88 ++++++++++++++++++++++++++++++--
2 files changed, 96 insertions(+), 7 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index ebc218840fc2..de89da76a379 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -6,6 +6,7 @@
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <linux/interrupt.h>
#include <kvm/iodev.h>
#include <kvm/arm_vgic.h>
@@ -942,8 +943,18 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg, bool allow_group1)
* generate interrupts of either group.
*/
if (!irq->group || allow_group1) {
- irq->pending_latch = true;
- vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ if (!irq->hw) {
+ irq->pending_latch = true;
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ } else {
+ /* HW SGI? Ask the GIC to inject it */
+ int err;
+ err = irq_set_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ true);
+ WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+ raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+ }
} else {
raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
}
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index d656ebd5f9d4..0a1fb61e5b89 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -5,6 +5,8 @@
#include <linux/bitops.h>
#include <linux/bsearch.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <kvm/iodev.h>
@@ -59,6 +61,11 @@ unsigned long vgic_mmio_read_group(struct kvm_vcpu *vcpu,
return value;
}
+static void vgic_update_vsgi(struct vgic_irq *irq)
+{
+ WARN_ON(its_prop_update_vsgi(irq->host_irq, irq->priority, irq->group));
+}
+
void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
unsigned int len, unsigned long val)
{
@@ -71,7 +78,12 @@ void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
raw_spin_lock_irqsave(&irq->irq_lock, flags);
irq->group = !!(val & BIT(i));
- vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ vgic_update_vsgi(irq);
+ raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+ } else {
+ vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
+ }
vgic_put_irq(vcpu->kvm, irq);
}
@@ -113,7 +125,21 @@ void vgic_mmio_write_senable(struct kvm_vcpu *vcpu,
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
raw_spin_lock_irqsave(&irq->irq_lock, flags);
- if (vgic_irq_is_mapped_level(irq)) {
+ if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ if (!irq->enabled) {
+ struct irq_data *data;
+
+ irq->enabled = true;
+ data = &irq_to_desc(irq->host_irq)->irq_data;
+ while (irqd_irq_disabled(data))
+ enable_irq(irq->host_irq);
+ }
+
+ raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+ vgic_put_irq(vcpu->kvm, irq);
+
+ continue;
+ } else if (vgic_irq_is_mapped_level(irq)) {
bool was_high = irq->line_level;
/*
@@ -148,6 +174,8 @@ void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu,
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
raw_spin_lock_irqsave(&irq->irq_lock, flags);
+ if (irq->hw && vgic_irq_is_sgi(irq->intid) && irq->enabled)
+ disable_irq_nosync(irq->host_irq);
irq->enabled = false;
@@ -167,10 +195,22 @@ unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu,
for (i = 0; i < len * 8; i++) {
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
unsigned long flags;
+ bool val;
raw_spin_lock_irqsave(&irq->irq_lock, flags);
- if (irq_is_pending(irq))
- value |= (1U << i);
+ if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ int err;
+
+ val = false;
+ err = irq_get_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ &val);
+ WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+ } else {
+ val = irq_is_pending(irq);
+ }
+
+ value |= ((u32)val << i);
raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
vgic_put_irq(vcpu->kvm, irq);
@@ -227,6 +267,21 @@ void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
}
raw_spin_lock_irqsave(&irq->irq_lock, flags);
+
+ if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ /* HW SGI? Ask the GIC to inject it */
+ int err;
+ err = irq_set_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ true);
+ WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+
+ raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+ vgic_put_irq(vcpu->kvm, irq);
+
+ continue;
+ }
+
if (irq->hw)
vgic_hw_irq_spending(vcpu, irq, is_uaccess);
else
@@ -281,6 +336,20 @@ void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
raw_spin_lock_irqsave(&irq->irq_lock, flags);
+ if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ /* HW SGI? Ask the GIC to inject it */
+ int err;
+ err = irq_set_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ false);
+ WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
+
+ raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+ vgic_put_irq(vcpu->kvm, irq);
+
+ continue;
+ }
+
if (irq->hw)
vgic_hw_irq_cpending(vcpu, irq, is_uaccess);
else
@@ -330,8 +399,15 @@ static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
raw_spin_lock_irqsave(&irq->irq_lock, flags);
- if (irq->hw) {
+ if (irq->hw && !vgic_irq_is_sgi(irq->intid)) {
vgic_hw_irq_change_active(vcpu, irq, active, !requester_vcpu);
+ } else if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
+ /*
+ * GICv4.1 VSGI feature doesn't track an active state,
+ * so let's not kid ourselves, there is nothing we can
+ * do here.
+ */
+ irq->active = false;
} else {
u32 model = vcpu->kvm->arch.vgic.vgic_model;
u8 active_source;
@@ -505,6 +581,8 @@ void vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
raw_spin_lock_irqsave(&irq->irq_lock, flags);
/* Narrow the priority range to what we actually support */
irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS);
+ if (irq->hw && vgic_irq_is_sgi(irq->intid))
+ vgic_update_vsgi(irq);
raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
vgic_put_irq(vcpu->kvm, irq);
--
2.20.1
Hi Marc,
On 2020/2/14 22:57, Marc Zyngier wrote:
> Most of the GICv3 emulation code that deals with SGIs now has to be
> aware of the v4.1 capabilities in order to benefit from it.
>
> Add such support, keyed on the interrupt having the hw flag set and
> being a SGI.
>
> Signed-off-by: Marc Zyngier <[email protected]>
> ---
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 15 +++++-
> virt/kvm/arm/vgic/vgic-mmio.c | 88 ++++++++++++++++++++++++++++++--
> 2 files changed, 96 insertions(+), 7 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index ebc218840fc2..de89da76a379 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -6,6 +6,7 @@
> #include <linux/irqchip/arm-gic-v3.h>
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> +#include <linux/interrupt.h>
> #include <kvm/iodev.h>
> #include <kvm/arm_vgic.h>
>
> @@ -942,8 +943,18 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg, bool allow_group1)
> * generate interrupts of either group.
> */
> if (!irq->group || allow_group1) {
> - irq->pending_latch = true;
> - vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
> + if (!irq->hw) {
> + irq->pending_latch = true;
> + vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
> + } else {
> + /* HW SGI? Ask the GIC to inject it */
> + int err;
> + err = irq_set_irqchip_state(irq->host_irq,
> + IRQCHIP_STATE_PENDING,
> + true);
> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> + }
> } else {
> raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> }
> diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
> index d656ebd5f9d4..0a1fb61e5b89 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio.c
> @@ -5,6 +5,8 @@
>
> #include <linux/bitops.h>
> #include <linux/bsearch.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> #include <kvm/iodev.h>
> @@ -59,6 +61,11 @@ unsigned long vgic_mmio_read_group(struct kvm_vcpu *vcpu,
> return value;
> }
>
> +static void vgic_update_vsgi(struct vgic_irq *irq)
> +{
> + WARN_ON(its_prop_update_vsgi(irq->host_irq, irq->priority, irq->group));
> +}
> +
> void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
> unsigned int len, unsigned long val)
> {
> @@ -71,7 +78,12 @@ void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
> irq->group = !!(val & BIT(i));
> - vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
> + vgic_update_vsgi(irq);
> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> + } else {
> + vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
> + }
>
> vgic_put_irq(vcpu->kvm, irq);
> }
> @@ -113,7 +125,21 @@ void vgic_mmio_write_senable(struct kvm_vcpu *vcpu,
> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
> - if (vgic_irq_is_mapped_level(irq)) {
> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
> + if (!irq->enabled) {
> + struct irq_data *data;
> +
> + irq->enabled = true;
> + data = &irq_to_desc(irq->host_irq)->irq_data;
> + while (irqd_irq_disabled(data))
> + enable_irq(irq->host_irq);
> + }
> +
> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> + vgic_put_irq(vcpu->kvm, irq);
> +
> + continue;
> + } else if (vgic_irq_is_mapped_level(irq)) {
> bool was_high = irq->line_level;
>
> /*
> @@ -148,6 +174,8 @@ void vgic_mmio_write_cenable(struct kvm_vcpu *vcpu,
> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
> + if (irq->hw && vgic_irq_is_sgi(irq->intid) && irq->enabled)
> + disable_irq_nosync(irq->host_irq);
>
> irq->enabled = false;
>
> @@ -167,10 +195,22 @@ unsigned long vgic_mmio_read_pending(struct kvm_vcpu *vcpu,
> for (i = 0; i < len * 8; i++) {
> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
> unsigned long flags;
> + bool val;
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
> - if (irq_is_pending(irq))
> - value |= (1U << i);
> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
> + int err;
> +
> + val = false;
> + err = irq_get_irqchip_state(irq->host_irq,
> + IRQCHIP_STATE_PENDING,
> + &val);
> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
> + } else {
> + val = irq_is_pending(irq);
> + }
> +
> + value |= ((u32)val << i);
> raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>
> vgic_put_irq(vcpu->kvm, irq);
> @@ -227,6 +267,21 @@ void vgic_mmio_write_spending(struct kvm_vcpu *vcpu,
> }
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
> +
> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
> + /* HW SGI? Ask the GIC to inject it */
> + int err;
> + err = irq_set_irqchip_state(irq->host_irq,
> + IRQCHIP_STATE_PENDING,
> + true);
> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
> +
> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> + vgic_put_irq(vcpu->kvm, irq);
> +
> + continue;
> + }
> +
> if (irq->hw)
> vgic_hw_irq_spending(vcpu, irq, is_uaccess);
> else
Should we consider taking the GICv4.1 support into uaccess_{read/write}
callbacks for GICR_ISPENDR0 so that userspace can properly save/restore
the pending state of GICv4.1 vSGIs?
I *think* we can do it because on restoration, GICD_CTLR(.nASSGIreq) is
restored before GICR_ISPENDR0. So we know whether we're restoring
pending for vSGIs, and we can restore it to the HW level if v4.1 is
supported by GIC. Otherwise restore it by the normal way.
And saving is easy with the get_irqchip_state callback, right?
> @@ -281,6 +336,20 @@ void vgic_mmio_write_cpending(struct kvm_vcpu *vcpu,
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>
> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
> + /* HW SGI? Ask the GIC to inject it */
"Ask the GIC to clear its pending state" :-)
Thanks,
Zenghui
> + int err;
> + err = irq_set_irqchip_state(irq->host_irq,
> + IRQCHIP_STATE_PENDING,
> + false);
> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
> +
> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> + vgic_put_irq(vcpu->kvm, irq);
> +
> + continue;
> + }
> +
> if (irq->hw)
> vgic_hw_irq_cpending(vcpu, irq, is_uaccess);
> else
> @@ -330,8 +399,15 @@ static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
>
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>
> - if (irq->hw) {
> + if (irq->hw && !vgic_irq_is_sgi(irq->intid)) {
> vgic_hw_irq_change_active(vcpu, irq, active, !requester_vcpu);
> + } else if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
> + /*
> + * GICv4.1 VSGI feature doesn't track an active state,
> + * so let's not kid ourselves, there is nothing we can
> + * do here.
> + */
> + irq->active = false;
> } else {
> u32 model = vcpu->kvm->arch.vgic.vgic_model;
> u8 active_source;
> @@ -505,6 +581,8 @@ void vgic_mmio_write_priority(struct kvm_vcpu *vcpu,
> raw_spin_lock_irqsave(&irq->irq_lock, flags);
> /* Narrow the priority range to what we actually support */
> irq->priority = (val >> (i * 8)) & GENMASK(7, 8 - VGIC_PRI_BITS);
> + if (irq->hw && vgic_irq_is_sgi(irq->intid))
> + vgic_update_vsgi(irq);
> raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>
> vgic_put_irq(vcpu->kvm, irq);
>
On 2020-02-18 08:46, Zenghui Yu wrote:
> Hi Marc,
>
> On 2020/2/14 22:57, Marc Zyngier wrote:
>> Most of the GICv3 emulation code that deals with SGIs now has to be
>> aware of the v4.1 capabilities in order to benefit from it.
>>
>> Add such support, keyed on the interrupt having the hw flag set and
>> being a SGI.
>>
>> Signed-off-by: Marc Zyngier <[email protected]>
>> ---
>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 15 +++++-
>> virt/kvm/arm/vgic/vgic-mmio.c | 88
>> ++++++++++++++++++++++++++++++--
>> 2 files changed, 96 insertions(+), 7 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> index ebc218840fc2..de89da76a379 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> @@ -6,6 +6,7 @@
>> #include <linux/irqchip/arm-gic-v3.h>
>> #include <linux/kvm.h>
>> #include <linux/kvm_host.h>
>> +#include <linux/interrupt.h>
>> #include <kvm/iodev.h>
>> #include <kvm/arm_vgic.h>
>> @@ -942,8 +943,18 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu
>> *vcpu, u64 reg, bool allow_group1)
>> * generate interrupts of either group.
>> */
>> if (!irq->group || allow_group1) {
>> - irq->pending_latch = true;
>> - vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
>> + if (!irq->hw) {
>> + irq->pending_latch = true;
>> + vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
>> + } else {
>> + /* HW SGI? Ask the GIC to inject it */
>> + int err;
>> + err = irq_set_irqchip_state(irq->host_irq,
>> + IRQCHIP_STATE_PENDING,
>> + true);
>> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
>> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>> + }
>> } else {
>> raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>> }
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio.c
>> b/virt/kvm/arm/vgic/vgic-mmio.c
>> index d656ebd5f9d4..0a1fb61e5b89 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio.c
>> @@ -5,6 +5,8 @@
>> #include <linux/bitops.h>
>> #include <linux/bsearch.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/irq.h>
>> #include <linux/kvm.h>
>> #include <linux/kvm_host.h>
>> #include <kvm/iodev.h>
>> @@ -59,6 +61,11 @@ unsigned long vgic_mmio_read_group(struct kvm_vcpu
>> *vcpu,
>> return value;
>> }
>> +static void vgic_update_vsgi(struct vgic_irq *irq)
>> +{
>> + WARN_ON(its_prop_update_vsgi(irq->host_irq, irq->priority,
>> irq->group));
>> +}
>> +
>> void vgic_mmio_write_group(struct kvm_vcpu *vcpu, gpa_t addr,
>> unsigned int len, unsigned long val)
>> {
>> @@ -71,7 +78,12 @@ void vgic_mmio_write_group(struct kvm_vcpu *vcpu,
>> gpa_t addr,
>> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>> irq->group = !!(val & BIT(i));
>> - vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
>> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
>> + vgic_update_vsgi(irq);
>> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>> + } else {
>> + vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
>> + }
>> vgic_put_irq(vcpu->kvm, irq);
>> }
>> @@ -113,7 +125,21 @@ void vgic_mmio_write_senable(struct kvm_vcpu
>> *vcpu,
>> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
>> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>> - if (vgic_irq_is_mapped_level(irq)) {
>> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
>> + if (!irq->enabled) {
>> + struct irq_data *data;
>> +
>> + irq->enabled = true;
>> + data = &irq_to_desc(irq->host_irq)->irq_data;
>> + while (irqd_irq_disabled(data))
>> + enable_irq(irq->host_irq);
>> + }
>> +
>> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>> + vgic_put_irq(vcpu->kvm, irq);
>> +
>> + continue;
>> + } else if (vgic_irq_is_mapped_level(irq)) {
>> bool was_high = irq->line_level;
>> /*
>> @@ -148,6 +174,8 @@ void vgic_mmio_write_cenable(struct kvm_vcpu
>> *vcpu,
>> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
>> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>> + if (irq->hw && vgic_irq_is_sgi(irq->intid) && irq->enabled)
>> + disable_irq_nosync(irq->host_irq);
>> irq->enabled = false;
>> @@ -167,10 +195,22 @@ unsigned long vgic_mmio_read_pending(struct
>> kvm_vcpu *vcpu,
>> for (i = 0; i < len * 8; i++) {
>> struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
>> unsigned long flags;
>> + bool val;
>> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>> - if (irq_is_pending(irq))
>> - value |= (1U << i);
>> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
>> + int err;
>> +
>> + val = false;
>> + err = irq_get_irqchip_state(irq->host_irq,
>> + IRQCHIP_STATE_PENDING,
>> + &val);
>> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
>> + } else {
>> + val = irq_is_pending(irq);
>> + }
>> +
>> + value |= ((u32)val << i);
>> raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>> vgic_put_irq(vcpu->kvm, irq);
>> @@ -227,6 +267,21 @@ void vgic_mmio_write_spending(struct kvm_vcpu
>> *vcpu,
>> }
>> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>> +
>> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
>> + /* HW SGI? Ask the GIC to inject it */
>> + int err;
>> + err = irq_set_irqchip_state(irq->host_irq,
>> + IRQCHIP_STATE_PENDING,
>> + true);
>> + WARN_RATELIMIT(err, "IRQ %d", irq->host_irq);
>> +
>> + raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
>> + vgic_put_irq(vcpu->kvm, irq);
>> +
>> + continue;
>> + }
>> +
>> if (irq->hw)
>> vgic_hw_irq_spending(vcpu, irq, is_uaccess);
>> else
>
> Should we consider taking the GICv4.1 support into uaccess_{read/write}
> callbacks for GICR_ISPENDR0 so that userspace can properly save/restore
> the pending state of GICv4.1 vSGIs?
>
> I *think* we can do it because on restoration, GICD_CTLR(.nASSGIreq) is
> restored before GICR_ISPENDR0. So we know whether we're restoring
> pending for vSGIs, and we can restore it to the HW level if v4.1 is
> supported by GIC. Otherwise restore it by the normal way.
>
> And saving is easy with the get_irqchip_state callback, right?
Yes, this should be pretty easy to do, but I haven't completely worked
out
the ordering dependencies (you're way ahead of me here!).
There is still a chance that userspace will play with us trying to set
and
reset nASSGIreq, so we need to define what is acceptable...
>
>> @@ -281,6 +336,20 @@ void vgic_mmio_write_cpending(struct kvm_vcpu
>> *vcpu,
>> raw_spin_lock_irqsave(&irq->irq_lock, flags);
>> + if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
>> + /* HW SGI? Ask the GIC to inject it */
>
> "Ask the GIC to clear its pending state" :-)
One day, I'll ban copy/paste from my editor... ;-)
M.
--
Jazz is not dead. It just smells funny...
On 2020/2/14 22:57, Marc Zyngier wrote:
> One of the new features of GICv4.1 is to allow virtual SGIs to be
> directly signaled to a VPE. For that, the ITS has grown a new
> 64kB page containing only a single register that is used to
> signal a SGI to a given VPE.
>
> Add a second mapping covering this new 64kB range, and take this
> opportunity to limit the original mapping to 64kB, which is enough
> to cover the span of the ITS registers.
Yes, no need to do ioremap for the translation register.
>
> Signed-off-by: Marc Zyngier<[email protected]>
Reviewed-by: Zenghui Yu <[email protected]>
Hi Marc,
On 2020/2/14 22:57, Marc Zyngier wrote:
> In order to let a guest buy in the new, active-less SGIs, we
> need to be able to switch between the two modes.
>
> Handle this by stopping all guest activity, transfer the state
> from one mode to the other, and resume the guest.
>
> Signed-off-by: Marc Zyngier <[email protected]>
[...]
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 1bc09b523486..2c9fc13e2c59 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm)
> goto out;
> }
>
> + if (kvm_vgic_global_state.has_gicv4_1)
> + vgic_v4_configure_vsgis(kvm);
> dist->ready = true;
>
> out:
Is there any reason to invoke vgic_v4_configure_vsgis() here?
This is called on the first VCPU run, through kvm_vgic_map_resources().
Shouldn't the vSGI configuration only driven by a GICD_CTLR.nASSGIreq
writing (from guest, or from userspace maybe)?
Thanks,
Zenghui
Hi Zenghui,
On 2020-02-20 03:55, Zenghui Yu wrote:
> Hi Marc,
>
> On 2020/2/14 22:57, Marc Zyngier wrote:
>> In order to let a guest buy in the new, active-less SGIs, we
>> need to be able to switch between the two modes.
>>
>> Handle this by stopping all guest activity, transfer the state
>> from one mode to the other, and resume the guest.
>>
>> Signed-off-by: Marc Zyngier <[email protected]>
>
> [...]
>
>> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
>> index 1bc09b523486..2c9fc13e2c59 100644
>> --- a/virt/kvm/arm/vgic/vgic-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-v3.c
>> @@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm)
>> goto out;
>> }
>> + if (kvm_vgic_global_state.has_gicv4_1)
>> + vgic_v4_configure_vsgis(kvm);
>> dist->ready = true;
>> out:
>
> Is there any reason to invoke vgic_v4_configure_vsgis() here?
> This is called on the first VCPU run, through kvm_vgic_map_resources().
> Shouldn't the vSGI configuration only driven by a GICD_CTLR.nASSGIreq
> writing (from guest, or from userspace maybe)?
What I'm trying to catch here is the guest that has been restored with
nASSGIreq set. At the moment, we don't do anything on the userspace
side, because the vmm could decide to write that particular bit
multiple times, and switching between the two modes is expensive (not
to mention that all the vcpus may not have been created yet).
Moving it to the first run makes all these pitfalls go away (we have the
final nASSSGIreq value, and all the vcpus are accounted for).
Does this make sense to you?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
Hi Marc,
On 2020/2/29 3:16, Marc Zyngier wrote:
> Hi Zenghui,
>
> On 2020-02-20 03:55, Zenghui Yu wrote:
>> Hi Marc,
>>
>> On 2020/2/14 22:57, Marc Zyngier wrote:
>>> In order to let a guest buy in the new, active-less SGIs, we
>>> need to be able to switch between the two modes.
>>>
>>> Handle this by stopping all guest activity, transfer the state
>>> from one mode to the other, and resume the guest.
>>>
>>> Signed-off-by: Marc Zyngier <[email protected]>
>>
>> [...]
>>
>>> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
>>> index 1bc09b523486..2c9fc13e2c59 100644
>>> --- a/virt/kvm/arm/vgic/vgic-v3.c
>>> +++ b/virt/kvm/arm/vgic/vgic-v3.c
>>> @@ -540,6 +540,8 @@ int vgic_v3_map_resources(struct kvm *kvm)
>>> goto out;
>>> }
>>> + if (kvm_vgic_global_state.has_gicv4_1)
>>> + vgic_v4_configure_vsgis(kvm);
>>> dist->ready = true;
>>> out:
>>
>> Is there any reason to invoke vgic_v4_configure_vsgis() here?
>> This is called on the first VCPU run, through kvm_vgic_map_resources().
>> Shouldn't the vSGI configuration only driven by a GICD_CTLR.nASSGIreq
>> writing (from guest, or from userspace maybe)?
>
> What I'm trying to catch here is the guest that has been restored with
> nASSGIreq set. At the moment, we don't do anything on the userspace
> side, because the vmm could decide to write that particular bit
> multiple times, and switching between the two modes is expensive (not
> to mention that all the vcpus may not have been created yet).
>
> Moving it to the first run makes all these pitfalls go away (we have the
> final nASSSGIreq value, and all the vcpus are accounted for).
So what will happen on restoration is (roughly):
- for GICR_ISPENR0: We will restore the pending status of vSGIs into
software pending_latch, just like what we've done for normal SGIs.
- for GICD_CTLR.nASSGIreq: We will only record the written value.
(Note to myself: No invocation of configure_vsgis() in uaccess_write
callback, I previously mixed it up with the guest write callback.)
- Finally, you choose the first vcpu run as the appropriate point to
potentially flush the pending status to HW according to the final
nASSGIreq value.
>
> Does this make sense to you?
Yeah, it sounds like a good idea! And please ignore what I've replied to
patch #15, I obviously missed your intention at that time, sorry...
But can we move this hunk to some places more appropriate, for example,
put it together with the GICD_CTLR's uaccess_write change? It might make
things a bit clearer for other reviewers. :-)
Thanks,
Zenghui